Many hardware MIDI controllers let you configure their buttons so they act as on/off toggle switches, rather than only being on when they are held down ("momentary"). However, not all controllers support this.

Here's a nifty trick to emulate a MIDI toggle switch for any module parameter in Magic. After linking the parameter to your desired MIDI button, add two modifiers with the values shown below:

MidiPowerToggle.png (19.68 KiB) Viewed 2439 times

This modifier sequence will make it so that whenever you press your MIDI button, the parameter value will continually toggle between 0 and 1. Try it out! And of course, let me know if you have any questions.